Our O line isnt as bad as the coaching made it look. Its also wasnt great in the middle for reasons of coaching, injury and continuity. I forget where it was dicussed, but i remember either Baldy or Schlereth remarking that the biggest problem with our line is that it gave up pressure up the middle at a rate that was near tops in the league. And pressure up the middle on a pocket passer affects the passing game more than pressure from the edge because it disrupts passing lanes and forces the qb to reset - there is no pocket to step up into.
Thats why trying to pick stats like time in pocket for us last year are misleading. The pocket wasnt entirely collapsed around Geno because we had decent Tackle play, but it was consistently pushed into his lap. Couple that with an OC that the HC kicked out the door as soon as he could after season's end (if there'd been a better option at passing game coordinator or assistant OC i think Mac woukd have fire him during the season) and you have protection thats not protecting and passing routes that even if you COULD see them were poorly conceived and often took too long to develop.
Grubb caused a lot of problems and you cant just look at one specific stat or advance stat to get the entire picture.